• Title/Summary/Keyword: Urban Environments

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Status of particulate matter pollution in urban railway environments (도시철도 환경의 미세먼지 오염 현황)

  • Kim, Jong Bum;Lee, Seung-Bok;Bae, Gwi-Nam
    • Journal of odor and indoor environment
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    • v.17 no.4
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    • pp.303-314
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    • 2018
  • The urban railway system is a convenient public transportation system, as it carries many people without increasing traffic congestion. However, air quality in urban railway environments is worse than ambient air quality due to the internal location of the source of air pollutants and the isolated space. In this paper, characteristics of particulate matter (PM) pollution in urban railway environments are described from the perspective of diurnal variation, chemical composition and source apportionment of PM. PM concentrations in concourse, platform, passenger cabin, and tunnel are summarized through an analysis of 34 journal articles published in Korea and overseas. This information will be helpful in developing effective policies to reduce PM pollution in urban railway environments.

Mapping Vegetation Volume in Urban Environments by Fusing LiDAR and Multispectral Data

  • Jung, Jinha;Pijanowski, Bryan
    • Korean Journal of Remote Sensing
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    • v.28 no.6
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    • pp.661-670
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    • 2012
  • Urban forests provide great ecosystem services to population in metropolitan areas even though they occupy little green space in a huge gray landscape. Unfortunately, urbanization inherently results in threatening the green infrastructure, and the recent urbanization trends drew great attention of scientists and policy makers on how to preserve or restore green infrastructure in metropolitan area. For this reason, mapping the spatial distribution of the green infrastructure is important in urban environments since the resulting map helps us identify hot green spots and set up long term plan on how to preserve or restore green infrastructure in urban environments. As a preliminary step for mapping green infrastructure utilizing multi-source remote sensing data in urban environments, the objective of this study is to map vegetation volume by fusing LiDAR and multispectral data in urban environments. Multispectral imageries are used to identify the two dimensional distribution of green infrastructure, while LiDAR data are utilized to characterize the vertical structure of the identified green structure. Vegetation volume was calculated over the metropolitan Chicago city area, and the vegetation volume was summarized over 16 NLCD classes. The experimental results indicated that vegetation volume varies greatly even in the same land cover class, and traditional land cover map based above ground biomass estimation approach may introduce bias in the estimation results.

Urban soundscape mapping based on GIS (GIS를 이용한 도시 사운드스케이프 지도화)

  • Hong, Joo Young;Kim, Jea Hyeon;Jeon, Jin Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.952-954
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    • 2014
  • Urban sound environments consists of various sound sources such as traffic noise, sounds of people and natural sounds affecting the perception of soundscape in a place. However, noise maps based on sound pressure levels could not distinguish different sound sources and limited to represent perception of acoustic environments. Accordingly, soundscape map based on perception of sounds is necessary to provide useful information for the description of the acoustic environment. Therefore, the aims of this study are to examine soundscape perception in different urban contexts including commercial, office, park and residential spaces and to suggest a method for soundscape maps using GIS techniques. Soundscape perceptions and physical characteristics of acoustic environments at various urban contexts were obtained from surveys and acoustic measurements, respectively. The results show that dominant factors affecting soundscape perceptions were different in urban contexts and spatial variations of urban soundscape are closely related to various urban contexts.

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An Evaluation of Pedestrian Environments based on the Criteria of Universal Design Theory - A case study of old town area in Seoul - (서울시 유니버설디자인 보행환경 조성을 위한 보행환경 평가 연구 - 서울시 사대문안 사례를 중심으로 -)

  • Jeong, Sangyun;Sohn, Dong-Wook
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.1
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    • pp.117-125
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    • 2019
  • The purpose of this study is to examine urban built environments associated with the walking behavior in order to identify the problem of urban infrastructure from the perspective of Universal design theory. Using the walkability criteria developed based on the findings of previous studies on Universal design theory and walking environment, the urban built environments in old town area of Seoul were evaluated. The results of the evaluation indicated that the pedestrian infrastructure in the study area had several shortcomings to improve in order to provide walking-friendly environments. First, the pedestrian infrastructure for visually impaired people were severely limited. Second, walking traffics in large portion of the street networks were interrupted by a variety of obstacles such as parked cars, signboards, and illegal street shops. Third, there were certain areas where the quality of pavement was not properly managed. In summary, this study provides an empirical data to understand the current situation of pedestrian infrastructure in the urban areas. Improvement of pedestrian infrastructure is needed to address the issues related to the mobility of the disabled people. It is also recommended to construct the GIS data on walking environment in order to develop and mange a long-term public investment plan for walking-friendly urban environments.

The Measurement and Consideration of Path Loss in Domestic Terrain Environments for IMT-2000 (국내지형환경에서의 IMT-2000주파수 대 경로손실 측정 및 고찰)

  • 이상수;이동진;최학근;김준철;박원진
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.12
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    • pp.547-552
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    • 2002
  • In this paper, the path loss in domestic terrain environments for IMT-2000 are measured and considered. Domestic terrain environments are classified and received power is measured at 1.9201GHz. In addition, the Path loss is calculated with consideration of the radiation pattern of antennas based on the results of measurement. For the consideration of path loss in domestic terrain environments, each path loss are fitted with the same slope of a reference model as "COST-231 HATA Urban Model", and then both are compared. As a result, all of the path loss in domestic terrain environments are lower than the path loss of a reference model as "COST-231 HATA Urban Model". We found that a difference of path loss in domestic terrain environments and a reference model is 5dB in urban, 8dB in sparse urban, 12dll in dense suburban, 13dB in suburban, 19dB in sparse suburban, and 29dB in road.

An Interpretation of Dualistic Relationships in an Urban Renewal Landscape Based on the Iching Theory - the Case of Gongpyeong District in Seoul - (괘상원리에 기초한 도심재개발 경관의 이원관계의 해석 - 서울 공평구역을 사례로 -)

  • 홍윤순
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.5
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    • pp.16-30
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    • 2002
  • This study tried to understand an ambiguous urban landscape through a relational context. Gongpyeong district, an urban renewal area in Seoul, was selected as the site of the case study because traditional and modern styles coexist in this district. The research method and processes are summarized as follows. First, the district, which has both a redeveloped environment and an inherent environment, was divided into Yin & Yang structures. Next, an effort was made to grasp the fundamental relational characteristics(external relationships) of each type through three aspects: physical environment, activities, and meaning. As a result, Yin characteristics were found in the redeveloped environment which has predominantly Yang characteristics. In many cases, advertising, which is a Yang element, was missing in the redeveloped area. On the other hand, in the inherent environment which has Yin characteristics in general, shabby appearances were evident in aspects beyond advertising, and Yang elements, were found from the viewpoint of the theory of place. On the basis of these results, new dualistic frameworks with respect to the functions were re-structured, and complementary characteristics (internal relationship) based on topological aspects were analyzed. Unlike the monotonous appearances found in large scale environments, a variety of spatial characteristics were found in the various small scale environments. This explains that the dualistic coexistence has made a contribution to the complementary attributes of urban landscape. This study has the following ramifications. Much research of urban landscapes that has used western methodology which employs analytic aspects. As a methodology of urban landscape research this study introduced Iching, which tries to understand phenomena in a relational context. In addition, this study expects that the profound understanding of urban environments and the detailed relationship through this framework will suggest a new approach to urban planning, design and management related to future urban environments.

Comparative Study on the Development Trends of High-rise Buildings Above 200 Meters in China, the USA and the UAE

  • Qu, Jiaqi;Wang, Zhendong;Du, Peng
    • International Journal of High-Rise Buildings
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    • v.10 no.1
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    • pp.63-71
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    • 2021
  • Since 2006, the number of completed high-rise buildings over 200 meters have increased rapidly. Although there were some short-term cyclical troughs, the overall trend has still been growing. No longer constrained by technological limits, the development of high-rise buildings now depends on cooperation and compromise between social, economic, and political factors. This article extracts statistical data from the Council on Tall Buildings and Urban Habitat (CTBUH) to focus on the completion of high-rise buildings of 200 meters and above over the past 20 years from 2000 to 2019. Similarities and differences in the number, distribution, and function of high-rise buildings are analyzed, The paper also compares the impact of different political and economic environments on the development trends of high-rise buildings in China, the United States and the UAE.

Fast Scene Understanding in Urban Environments for an Autonomous Vehicle equipped with 2D Laser Scanners (무인 자동차의 2차원 레이저 거리 센서를 이용한 도시 환경에서의 빠른 주변 환경 인식 방법)

  • Ahn, Seung-Uk;Choe, Yun-Geun;Chung, Myung-Jin
    • The Journal of Korea Robotics Society
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    • v.7 no.2
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    • pp.92-100
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    • 2012
  • A map of complex environment can be generated using a robot carrying sensors. However, representation of environments directly using the integration of sensor data tells only spatial existence. In order to execute high-level applications, robots need semantic knowledge of the environments. This research investigates the design of a system for recognizing objects in 3D point clouds of urban environments. The proposed system is decomposed into five steps: sequential LIDAR scan, point classification, ground detection and elimination, segmentation, and object classification. This method could classify the various objects in urban environment, such as cars, trees, buildings, posts, etc. The simple methods minimizing time-consuming process are developed to guarantee real-time performance and to perform data classification on-the-fly as data is being acquired. To evaluate performance of the proposed methods, computation time and recognition rate are analyzed. Experimental results demonstrate that the proposed algorithm has efficiency in fast understanding the semantic knowledge of a dynamic urban environment.

Changes of Attitudes towards Old Urban Environments in the Comprehensive Plans of Seoul, from 1966 through 2014 (서울도시기본계획에서 나타난 오래된 도시 환경에 대한 태도 변화 - 1966년 기본계획에서 2030 서울플랜까지 -)

  • Kee, Sehwang;Park, So-Hyun
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.2
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    • pp.11-22
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    • 2019
  • The purpose of this study is to explore changing attitudes towards old urban environments, represented in the comprehensive plans of Seoul, from the first 1966 plan through the most recent one of 2014. The results of analyzing all 6 Seoul urban comprehensive plans are as follows. The contents for considerations and actual planning actions for old urban environments were presented from the third comprehensive plan of 1990. The term 'historical heritage' was first applied in the urban park planning of the 1996 plan. In the 4th comprehensive plan of 1997, it began to regard historical landscapes as 'precious heritages' to make plans for using historical heritages in parts of landscape, education, and tourism. The scope of 'historical heritage' in the comprehensive plans has been expanded. This tendency continued to expand in the 5th plan of 2006, and again in the 6th plan of 2014. At the same time, in pursuing the identity of Seoul, 'historical heritage' in old urban environment came to be materialized further as planning objects.

Urban geology of Tabriz City: Environmental and geological constraints

  • Azarafza, Mohammad;Ghazifard, Akbar
    • Advances in environmental research
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    • v.5 no.2
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    • pp.95-108
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    • 2016
  • Urban geology is the study of urban geologic environments to provide a scientific basis for rational land use planning and urban development and provides information on geologic environments as a basis for city planners. Based on AEG recommendations, urban geological studies covered the urbanism and historical backgrounds, geological setting, engineering geological constraints and environmental assessments of understudied cities. The aim of this study is to provide a good view of urban geology of Tabriz city the capital of East Azerbaijan province in Iran. The topics of discussions about Tabriz city urban geology are included geologic (geomorphology, geology, climatology and hydrogeology), engineering geological (earthquake, landslide and geotechnical hazards investigations) and environmental characteristics (air, soil and water hazards assessment).The results of the urban geologic studies indicated that Tabriz city in terms of engineering geological and environmental constraints is at high risk potential and in terms of seismic activity and landslide instability is highly potential. In terms of air, soil and water pollution there are many important environmental concern in this city.